Evolution of ore-forming fluids at the Grøntua eSMS deposit
This Master's project was assigned to Vegard Pettersen who started the Master's program in Earth sciences, UiB, fall 2025. The Master's project is given by the research group Geochemistry and Geobiology.
Hovedinnhold
Geological factors that control preservation of extinct seafloor massive sulfide (SMS) deposits: A case study of the newly discovered Grøntua eSMS deposit, the Arctic Mid Ocean Ridges Seafloor massive sulfide (SMS) mineralization represents the recent analogue of ancient volcanogenic massive sulfide (VMS) deposits preserved on land. Although the SMS mineralization has been a subject of multidisciplinary research teams since the first finding of seafloor hydrothermal vents back in 1970s, the mechanism of preservation of sulfide[1]bearing mineral parageneses in extinct seafloor massive sulfide (eSMS) deposits is still unclear.
The Grøntua deposit is a newly discovered eSMS located at the Mohns Ridge of the Arctic Mid Ocean Ridges. The deposit was found during a research cruise led by Center for Deep Sea Research of UiB in summer 2024. It is located at a depth of approximately 1175 mbsl, has a diameter of 150 m and extends 60 m above the seafloor. The area was revisited and additionally sampled in March/April 2025.
This deposit represents an ideal site to study geological processes that control the fate of SMS mineralization after a seafloor hydrothermal system goes from its active to the extinct phase.
1) The main goal of Master project #1 (Mineral characteristics of the Grøntua eSMS deposit) is to collect textural, mineralogical, chemical and sulfur isotope data and identify possible preservation mechanisms. The study will combine phase analyses (transmitted and reflected microscopy, X-ray diffraction, Raman spectroscopy), major and trace element analyses (SEM/EDS, LA-ICP-MS) and sulfur isotope analyses of individual mineral phases.
2) The main goal of Master project #2 (Evolution of ore-forming fluids at the Grøntua eSMS deposit) is to link textural and mineralogical characteristics of the hydrothermal alteration zones with fluid inclusion data. The study shall give an insight into transport mechanism of Cu and associated elements (Zn, Co, Au, etc) in the study area. The project will combine phase analyses (transmitted and reflected microscopy, X-ray diffraction, Raman spectroscopy) with fluid inclusion study (petrography, microthermometry, Raman spectroscopy).